Electric meter.



G. A. SOHBEFPER.

ELEGTRIO METER:

APPLICATION FILED JAN. 2, 1904.

950,079. Patented Feb. 22, 1910.

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Scheefier G. A. SOHEEFPER.

ELECTRIC METER.

APPLICATION FILED JAN. 2, 1904.

Patented Feb. 22, 1910.

3 SHEETS-SHEET 2.

w 6 S 5 61 n G. A. SGHEEFFER.

ELECTRIC METER.

APPLICATION FILED JAN. 2, 1904.

950,079. Patented Feb. 22, 1910.

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UNITED srnrnsrngnnr QFFICE.

GUST-AVEA. SCI-IEIEFF-ER, 'OF FORT WAYNE, INDIANA, ASSIGNOR TO GENERAL ELECTRIC COMP-ANY, -A. CORPORATION OF NEW YORK.

nnno'rnio METER.

Specification of Letters Patent.

Gontinuation of abandoned application Serial No. 123,050, filed September 12, 1902. This application filed I January 2, 190-4. Seria1 No. 187,437. 1

[0 all whom it may concern:

Be it known that I, GUSLAVE A. Scnnnrrnn, a citizen of the United States, residing at Fort Wayne, county of Allen, State of Indiana, have invented certain new and useful Improvements in Electric Meters, of which the following is a specification.

My invention relates to alternating current electric meters of the induction motor ty e. The object of my invention is to produce a new and improvedmeter for measuring alternating electric currents, which shall be' accordance with my invention with the case removed; Fig. 2 shows the same with the indicating dial and its mechanism removed; Fig. 3 is a plan view of the same; Fig. 4 is a side elevation looking from the right of Fig. 1; Fig. 5 shows the core of the primary member with the positions of the coils indicated in dotted lines; Figs. 6 and 7 are detail views of the support for the moving parts; and Fig. 8 is a detail view of my friction compensating device.

The meter comprises a primary member consisting of a core B which, as is usual in the construction of cores of alternating-current apparatus, is built up of iron or soft steel plates suitably clamped together, a closed metallic armature consisting of a disk of copper or aluminum free to rotate in suitable bearings, a registering movement, a. damping magnet, and shunt and series windings, the shunt windings being mounted on the core and the series windings in close proximity to the meter armature.

Referring first to Fig. 5 of the drawing, it will be seen that the primary member consists of a rectangular core of magnetic material having an air-gap a at one end thereof and projecting poles intermediate the ends. In the particular construction shown in the drawing, the rectangular core is made up of a [shaped member B with two inwardlyprojecting pole-pieces B B separated by a small air-gap a at the extremities of the limbs of the E shaped member, and two more projecting pole-pieces B B which are located intermediate the ends of the limbs. The inner ends of the pole-pieces B B are separated from each other by an air-gap large enough to permit the armature disk to rotate freely therein, and the pole-pieces B B are separated by an air-gap large enough to cause the desired intensity of the magnetic flux through the pole-pieces B B and the armature of the meter.

Two shuntcoils G G havinga large number of turns of relatively fine wire are mounted one on each limb of the E shaped core on the side of the pole-pieces B B away from the air-gap a, and the magnetic flux generated by these coils flowsin two parallel paths through the two sets of polepieces B B and B B the meter armature being influenced only by that part of the shunt flux which passes through the air-gap between the pole-pieces B B Two series coils H H having relatively few turns of large wire, which carries the current to be measured, are located between the two sets of pole-pieces one above and the other below the armature disk. The series coils are preferably two in number, in order to secure a balancedand symmetrical arrangement, and they are located in close proximity to the armature. Except for the purpose of securing a symmetrical arrangement one series coil located either above or below the armature would answer. i

, Vith the primary member constructed in accordance with the principles of my prescut invention, I avoid the use of an impetare-shaft bearings.

very small, in order to reduce to a minimum the vibration of the-armature produced by induction from the core so as to avoid the rapid wear of the jewel used in the arma- The shunt flux must also be small in. order to avoid a checking effect on the accuracy ofthe meter under different conditions; that is, in order that variations of voltage should have little eflect on the accuracy of the meter.

In its general construction my meter is exceedingly small and compact. The 'primary member carrying the shunt and series coils is supported on posts from the back of the meter casing A, and all the working,

parts of the meter are supported directly from the primary member. The bearings. for the shaft con which themeter a rmature C is mountedare supported by two integral lugs or extensions d d projecting from a plate D wliichserves as a clamping plate for securing the 'lan'iina'tions of the primary member together. The plate together with its projectinglugs'constitutes a frame which is stamped 'out of sheet-metal in the form shown in Fig. 6,-and then the lugs or exteu sions (Z (Z .are turned up so that they are substantially at right angles to'the body of the frame, as' sh'own in Fig. 7. As the frame with its projecting lugs and the bending of the latter isprodu'ced in the stamping press, it will be evident that the frame may be produced rapidly and economically and that all frames will be'exact duplicates. lVith such a construction it"is easy to position the arniatlire-shaft"bearings with absolute accuracy with respect to the primary member of the ineter,'and since the frame and projecting lugs'ar e made on one piece, the bearings for thefrot a-tii'xg armatu'reshaft will never change their position. andthe shaft will remain permanently in proper and accurate alinel'nent.

The damping inagnetE' in my meter is arranged "to act on the armature disk at a point removed from theshunt and'sei'ies coils, and this magnet is'adj'ustably sup; ported b'yf'me'a'ns' of brackets F secured to the upper part of the'primary member, the adjustment being obtained by loosening the screws f and moving the nnignet-away from or toward the armaturc-shaft.

If a meter is mounted in such a place that it is subject to jar or vibration, the effect. of the jar upon the jeweled thrust-bearing for the vertical armature-shaft is injurious. By my invent'ionI provide means for decreasing the vibrationof the moving parts. A

I is al'stiip' of "ron secured to the permanent magnet E. strip J" 'wjhi c h"-eittencls' into close proximity to the s'haft d of thmoving parts-as shown in Fig.-"3.-- Strip l is magnetized by permaw nentmagnet E to which it is magnetically,

connectiby stripL gand thus acts. as a Hi l I. (I 5 I I v damping magnet for the shaft 0, The axial vibration of the vertical shaft is thus decreased and the chance of injury to the thrust-bearing is diminished. However light the moving parts of the meter may be and in however'goodtcondition the bearings may be, nevertheless there is necessarily some friction which liable to produce error. atstarting and on light loads, unless it is compensated for. To effect the compensation for the friction I provide the'small piece of iron L carried by the bent wire K, which is clamped to the primary member by the screw 70. The iron piece L is placed in close proximity to one of the poles B of the primary member and produces a distortion ofthe field atthepole, which increases the starting torque and thus compensates for friction: 'By'loosening screw is and adjusting the support K so as to bring piece L nearer to, or farther away from, the surface of disk C the compensating effect of pietpe C may be adjusted.

I do not desireto limit myself to the particular construction and arrangement of parts here shown, since changes. therein, which do notdepart from the spirit of my invention and which are in the scope of the appended claims, will be obvious to those skilled in the art. I

\Vhat I claim as new and desire to secure by Letters Patent of the United States, is,--

1. In an electric meter, a rectangular core of magnetic material having an air--gap cutting one of the shorter sides of the rectangle and poles projecting toward each other froml points near the centers of the longer sides of the rectangle, a shunt winding surrounding the core and so positioned that the shortest magnetic circuit therefor is through that portionof the rectangle having a closed magnetic circuit and through the projecting poles, and a disk armature projecting be tween said projecting poles.

2. In an electricmeter, a core of magnetic material shaped to constitute an almost completely closed magnetic circuit having only. a

small air-gap between its adjacent ends ,fprojecting poles extending from said core, a shunt winding so positioned onthe core that its shortest magnetic circuit is through a portion of the coreJhaving a closed magnetic circuit and through the said projecting poles, a series winding in the space between the projecting poles and the end of the rectangle having the air-gap, and an armature of conducting; material projecting between said poles and in inductive relation to said a series windin Str1p Icarries the non v 3. In an electric meter, a rectangular core of magnetic material having an air-gap at one end thereofand projecting poles intermediate the ends, a shunt winding surrounding the core in the space between the projecting poles and the end of the rectangle having the air-gap, a series winding on that side of the pro ecting poles ad acent to the air-gap, and a disk armature pro ecting between the poles and in inductive relation to I the series winding.

4:. In an electric meter, a rectangular core of magnetic material having an air-gap at one end thereof and projecting poles intermediate the ends, a shunt winding comprising t-wo coils surrounding the two limbs of the rectangular core adjacent to the end having a closedmagnetic circuit, a disk armature projectingbetween the said intermediate poles, and a series winding comprising two coils located one above and one below the said armature in the space between the projecting poles and that end of the rectangular core having the air-gap.

In an electric meter, an armature of conducting material, a series winding adjacent thereto, and a shunt winding provided with a I: shaped core of magnetic material having a plurality of sets of inwardly-projecting poles, the magnetic flux of part of said poles acting on said armature.

6. In an electric meter, an armature of conducting material, a series winding comprising two coils one on each side of said armature and in close proximity thereto, and a. shunt winding provided with a E shaped core of magnetic material, having a plurality of sets of inwardly-projecting poles,- the ma gnetic flux of part of said poles acting on the said armature.

7. In an electric meter, a movable armature, a vertical shaft therefor, a jeweled thrust-bearing supporting the weight of said armature and shaft, a damping magnet opposing rotation of the armature, and means comprising a magnetic member continuously operative during normal operation of the meter for preventing axial vibration of the shaft.

8. In an electric meter, a movable armature, a "ertical shaft therefor of conducting material, a jeweled thrust-bearing supporting the weight of said armature and shaft, and a continuously magnetized member extendiiw into close proximity to said shaft for preventing axial vibration thereof.

9. In an electric meter, a movable armature, a vertical shaft therefor of conducting material, a jeweled thrust-bearing supporting the weight of armature and shaft, a damping magnet opposing rotation of the armature, and a continuous flux damping magnet opposing axial movement of the shaft.

10. In an electric meter, a movable armature, a vertical shaft therefor, a jeweled thrust-bearing supporting the weight of armature and shaft, a damping magnet op posing rotation of the armature, and a strip of magnetic material magnetized by said magnet and extending into close proximity to the shaft of said armature for preventing axial vibration thereof.

In witness whereof, I have hereunto set my hand this 29th day of December, 1903.

GUSTAY E A. SCHEEFFER. Witnesses i JAMES J. \Voon, N. N. KING. 

